Regulating the Coordination\nEnvironment of Single-Atom\nCatalysts Anchored on Thiophene Linked Porphyrin for an Efficient\nNitrogen Reduction Reaction

Abstract

The electrochemical nitrogen reduction reaction (NRR)\noffers a\npromising strategy to resolve high energy consumption in the nitrogen\nindustry. Recently, the regulation of the electronic structure of\nsingle-atom catalysts (SACs) by adjusting their coordination environment\nhas emerged as a rather promising strategy to further enhance their\nelectrocatalytic activity. Herein, we design novel SACs supported\nby thiophene-linked porphyrin (TM–N₄/TP and TM–N_4‑<i>x</i>B_<i>x</i>/TP,\nwhere TM = Sc to Au) as potential NRR catalysts using density functional\ntheory calculations. Among these catalysts, TM–N₄/TP (TM = Ti, Nb, Mo, Ta, W, and Re) and TM–N₄/TP\nwith a water bilayer (TM = Nb, Mo, W, and Re) show excellent activity\n(low limiting potential) but low selectivity. Encouragingly, we find\nthat Mo–N₃B/TP, Mo–N₂B₂-2/TP, W–N₃B/TP, W–N₂B₂-2/TP, Re–N₃B/TP, Re–N₂B₂-2/TP, and Re–N₂B₂-1/TP serve\nas the most efficient NRR electrocatalysts, as they present stability,\nsuperior activity, better selectivity with low limiting potentials\n(−0.18 ∼ −0.90 V), and high Faradaic efficiencies\n(>99.80%). Based on microkinetic modeling, kinetic analysis of\nthe\nNRR is performed and shows that the Re–N₂B₂-1/TP catalyst is more efficient for NH₃ formation. Additionally,\nmultiple-level descriptors provide insight into the origin of NRR\nactivity and enable fast prescreening among numerous candidates. This\nwork provides a new perspective to design highly efficient catalysts\nfor the NRR under ambient conditions.